The present invention relates to a solar energy collector assembly, and more specifically to a solar energy collector assembly comprising a tubular collector unit having a solar energy absorber member and a reflector. A nontracking type of solar energy collectors is disclosed, for example, in Japanese Preliminary Publication 53-727158 (corresponds to U.S. application Ser. No. 727158 filed by R. H. Hefflfinger on Sept. 27, 1976), in Japanese Preliminary Publication 53-24144 (corresponds to U.S. application Ser. No. 714,724 filed by R. J. Bealinger et al on Aug. 16, 1976).
Heffelfinger discloses a solar collector unit comprising an evacuated, double-glass walled, tubular housing, a coating disposed on the outer surface of the inner glass tube and made of a material highly absorbent of solar rays; a tubular sheet metal fin contained within the housing and biased against the inner wall of the housing, and a metal tube provided to allow water to flow therein in good heat transfer relationship with the fin. While being advantageous to collect sufficiently solar energy independently of the incidence angle thereof, the above described collector unit experiences the following problems:
(1) Material cost was relatively high; PA0 (2) The tubular collector unit was relatively difficult to manufacture because the evacuated, double-glass walled tubular housing was complicated in structure; and PA0 (3) The tubular collector unit gave unsatisfactory heat transfer relationship between the tubular sheet metal fin and the inner glass wall because each of the fin and the inner glass wall might be bent or rough along its axial length, thus reducing the efficiency of solar energy collection.